1. Technical Field
The disclosure relates generally to integrated circuit (IC) chip package processing, and more particularly to the production of IC chip packages using a solid grid to prevent the formation of micro solder balls.
2. Background Art
The production of integrated circuit (IC) chips including Controlled Collapse Chip Connections (C4s) is currently plagued by a yield loss problem caused by the formation of micro solder balls during chip join processes. These defects are caused by solder on the substrate being squeezed out from under a C4 to such extent that the solder on two adjacent pads touch each other. Surface tension between the solder C4s causes the solder to form into micro solder balls. The presence of micro solder balls has been shown to negatively impact shipped product quality level and field reliability of the IC chip packages containing them.
An additional challenge in IC chip package processing is C4 to C4 shorting, caused by the formation of defects known as geodes. Geodes are caused by the outgassing of organics in a C4, resulting in hollow C4s that grow in size to such an extent that they touch, and the gap between them is bridged, causing a short.